TNO, the Dutch applied research institute, is developing an ultra-thin perovskite solar film designed to be applied directly to the surface of caravans and motorhomes, with the aim of bringing it to market within about four years. The project is backed by close to €50 million in subsidies. Many caravans and RVs already carry solar panels, but conventional panels add substantial weight - a real constraint given that these vehicles can easily exceed their maximum allowed weight. TNO's film is desi